1. Field of the Invention:
This invention relates to a hydraulic reservoir in a tandem master cylinder for a vehicle.
2. Description of the Prior Art:
Generally, a tandem master cylinder includes a hydraulic reservoir for reserving brake fluid. The hydraulic reservoir consists of a main portion defining a fluid reservoir chamber, and two brake fluid supply portions defining fluid paths respectively, and being formed under the main portion. The two brake fluid supply portions are contiguous with the mainportion. The fluid reservoir chamber of the main portion communicate with the fluid paths of the two brake fluid supply portions. The top of the main portion is formed as an opening. The two brake fluid supply portions are connected to brake fluid connection portions of a tandem master cylinder body, respectively. The fluid paths of the brake fluid supply portions communicate with fluid pressure generating chambers of the tandem master cylinder body. A cap is fitted to the opening of the main portion of the hydraulic reservoir. The reservoir is made of synthetic resin so that it is light, and the level of brake fluid in the reservoir can be observed from the exterior.
The hydraulic reservoir is relatively complicated in shape. In the manufacture of the hydraulic reservoir, an upper part including the opening, and a lower part including the brake fluid supply portions are separately formed, and the formed upper and lower parts are heat-welded with each other to obtain the hydraulic reservoir as one body. However, there are some problems on mechanical strength and reliability of sealing property in the welded portion of the thus obtained hydraulic reservoir. Further, the welding operation is inferior in productivity and labor efficiency.